""The calls started flooding in from hundreds of irate North Carolina voters just after 7 a.m. on Election Day last November.
Dozens were told they were ineligible to vote and were turned away at the polls, even when they displayed current registration cards. Others were sent from one polling place to another, only to be rejected. Scores of voters were incorrectly told they had cast ballots days earlier. In one precinct, voting halted for two hours.
Susan Greenhalgh, a troubleshooter at a nonpartisan election monitoring group, was alarmed. Most of the complaints came from Durham, a blue-leaning county in a swing state. The problems involved electronic poll books — tablets and laptops, loaded with check-in software, that have increasingly replaced the thick binders of paper used to verify voters’ identities and registration status. She knew that the company that provided Durham’s software, VR Systems, had been penetrated by Russian hackers months before.
“It felt like tampering, or some kind of cyberattack,” Ms. Greenhalgh said about the voting troubles in Durham.
There are plenty of other reasons for such breakdowns — local officials blamed human error and software malfunctions — and no clear-cut evidence of digital sabotage has emerged, much less a Russian role in it. Despite the disruptions, a record number of votes were cast in Durham, following a pattern there of overwhelming support for Democratic presidential candidates, this time Hillary Clinton.
But months later, for Ms. Greenhalgh, other election security experts and some state officials, questions still linger about what happened that day in Durham as well as other counties in North Carolina, Virginia, Georgia and Arizona.
After a presidential campaign scarred by Russian meddling, local, state and federal agencies have conducted little of the type of digital forensic investigation required to assess the impact, if any, on voting in at least 21 states whose election systems were targeted by Russian hackers, according to interviews with nearly two dozen national security and state officials and election technology specialists.
The assaults on the vast back-end election apparatus — voter-registration operations, state and local election databases, e-poll books and other equipment — have received far less attention than other aspects of the Russian interference, such as the hacking of Democratic emails and spreading of false or damaging information about Mrs. Clinton. Yet the hacking of electoral systems was more extensive than previously disclosed, The New York Times found.